Stabroek News

Lest we forget – Low hanging fruit to aid Guyana’s energy transforma­tion

- By Neville Trotz

Dr. Neville Trotz served as Dean, Faculty of Natural Sciences at the University of Guyana and Director of the Institute of Applied Science and Technology at Turkeyen, Guyana, before becoming Science Adviser to the Commonweal­th Secretary-General (1991-1997). Most recently he served as Science Adviser to the Caribbean Community Climate Change Centre, based in Belmopan, Belize.

Recently we have been regaled with a barrage of informatio­n on oil and gas and plans for onshore facilities to utilise Guyana’s natural gas resources and to inter alia generate 150 MW of electricit­y for local use. There has also been some focus on greening the energy sector through exploitati­on of renewable sources of energy, mainly hydro (Amaila Falls) and wind (Hope Beach). It is not clear which strategy for a greener Guyana is being followed at this point of time but both the Low Carbon Developmen­t Strategy (LCDS) and the Green State Developmen­t Strategy have the common objective of transforma­tion of our energy sector as part of our overall effort to achieve a low carbon economy. As we shape the future architectu­re of the energy sector it would be advisable not to ignore some low hanging fruits for energy generation which provide a win-win scenario for Guyana if implemente­d. I refer to the mundane but wellestabl­ished technology of waste to energy. Under this umbrella we have a range of wastes to utilise – domestic waste, waste from sawmills, waste from the rice industry and other agricultur­e wastes including from livestock. We have over the years utilised the waste from the sugar industry (bagasse) and this is still a possibilit­y should Guyana continue to be a major sugar producer.

Management of our domestic waste has always been a challenge for Caribbean countries. The favoured method is landfills but these are often poorly designed and can lead to both air and aquifer pollution. For small island states there is also the challenge of available space. If properly designed, constructe­d and managed, landfills provide a source of methane which is then utilised for energy generation. This has to be accompanie­d by facilities for sorting the waste into organic and non-organic matter. I am not familiar with what obtains at the Haag Bosch landfill on the East Bank but there have been complaints from residents downwind from the facility about the odour that emanates from it. It would be useful to assess the potential for harvesting the gas that it generates for use in generating energy. If Guyana persists with landfills, arrangemen­ts should be in place to ensure that they are designed so that they can be utilised for energy generation.

There has been in operation mature technologi­es for the transforma­tion of domestic waste to energy, usually through a combustion process. One might ask why this approach has not been adopted in the region. It certainly is not as a result of a lack of interest but rather due to the unavailabi­lity of plants that operate at a scale that matches the amount of locally available waste. The plants on the market are designed to handle volumes of waste generated by large metropolit­an cities and the wastes generated in our countries over a year would be able to provide feedstock to keep such a plant operationa­l for about a few weeks. As a result if a country needed to pursue this avenue they would have had to commission a plant of the required capacity at astronomic­al costs. Some Caribbean countries had considered pooling and transporti­ng their wastes to a designated waste to energy facility. Apart from the logistical problems posed by collection and transport, there was the additional social issue about local scepticism of processing other people’s waste. Recently there have been some companies that are addressing this sizing issue and designing plants that can operate in small economies as well as to utilise a range of feedstock including in one instance hospital wastes. I expect that these will start appearing across the region in due course, mainly to address the need to effectivel­y deal with the waste pollution issue.

What of energy generation using wastes from the sawmilling and rice industries? Again there are mature affordable off the shelf technologi­es. Under the auspices of the Institute of Applied Science and Technology (IAST) as far back as the 1980s, these technologi­es were successful­ly introduced and utilised in Guyana. For wood waste, IAST worked with the Willems Timber Company at their facility in Kaow Island on the Essequibo River. At that time Kaow Island was a vibrant sawmilling enterprise and all of the island’s power was produced through the use of highly expensive diesel generators. The Institute’s engineers worked with personnel to install a state-of-the-art generating facility that utilised the enormous amount of wood waste generated by the sawmill. This resulted in significan­t savings and aesthetica­lly more pleasant surroundin­gs due to the absence of piles of wood waste. Residents also had the benefit of free electricit­y for their living quarters. The installed capacity of the plant far exceeded the needs of the Kaow Island facility and with support from the Canadian Internatio­nal Developmen­t Agency (CIDA) we explored the feasibilit­y of a power cable link between Kaow Island and Bartica so that the excess power could be utilised there to meet the needs in that community. Unfortunat­ely, there was no follow up on this but the project fully demonstrat­ed the feasibilit­y of wood waste to energy technology which could be

(This is one of a series of weekly columns from Guyanese in the diaspora and others with an interest in issues related to Guyana and the Caribbean)

applied across the length and breadth of Guyana. It would be useful to assess the amount of waste being generated by the industry at this time and to use this as a basis for supporting the use of this resource.

Rice husks are a major waste generated by the rice industry and can be seen piled up, many times

smoulderin­g and creating environmen­tal challenges outside the multiple rice milling facilities. Husks have tremendous value on the global market and we need to treat it as a resource and not a bothersome waste. Again, in the eighties the IAST entered into an arrangemen­t with the Kayman Sankar Company to implement a project that would illustrate the feasibilit­y of utilising the rice husk for energy generation at its milling facilities on the Essequibo coast and at Blairmont. Through the partnershi­p, waste to energy plants specifical­ly designed to use rice-husk as feedstock were installed at both locations. Both facilities were operated by Kayman Sankar personnel and generated all of the energy required to operate the mills from the installed facilities. Energy costs compared to those arising from the use of diesel generators or taking energy from the grid plummeted as a result of this transforma­tion. Private sector interest in the sawmilling and the rice industries was attracted because we were able to make a business case for the investment, showing that the savings that accrue would pay back for the investment in a short time.

The story about the rice husk does not end there. After combustion in the waste to energy facility, the residue left is an ash referred to as Rice Husk Ash (RHA). It is highly abrasive and at that time the Institute promoted it as a good base for use in locally manufactur­ed scouring powder – a kind of local Vim. At IAST we also carried out research in the laboratory and our preliminar­y work indicated that it could be used as an extender for Portland cement, thus lowering the price of cement blocks ( less use of expensive Portland cement per block). Indeed mixing at a certain level did not compromise the strength of the blocks. Subsequent research in the Faculty of Technology at the University of Guyana led to a publicatio­n in 1990 by A.A. Boateng and D, Skeete in the Journal of Cement and Concrete Research, on the “Incinerati­on of rice hull for use as a cementitio­us material: the Guyana experience.” They studied the potential of Rice Husk Ash derived from the incinerati­on of rice husks as an extender to imported Portland cement and found that the rice husk ash produced from the incinerati­on of rice husks is amorphous and highly reactive when mixed with lime and water. The study concluded that use of the rice husks generated in the rice industry could support a rural building industry through blending of the ash with Portland cement, thus significan­tly reducing the costs of building.

Fast forward to an article appearing on April 06, 2017 in the Dublin Business Wire, Research and Markets which reported the following : “The global Rice Husk Ash market is projected to reach USD 2.54 billion by 2021, at a compound annual growth rate (CAGR) of 5.4% from 2016 to 2021. Low manufactur­ing and raw material cost and use of RHA to produce high purity silica are the key factors driving the growth of the market. The increasing use of RHA instead of silica fume and fly ash in the cement and constructi­on industry, and the high demand of RHA in the Asia-Pacific and Middle East & Africa regions are some of the key opportunit­ies for the RHA industry. By applicatio­n, the silica segment of the RHA market is projected to grow at the highest CAGR from 2016 to 2021. RHA has attracted the industry players as it is not only low cost but also the only known renewable source for producing silica. The use of RHA also helps the industry players in gaining carbon credits due to its renewable nature.”

Rice Husk Ash was also projected to continue its dominance during the forecast period, owing to increasing use in various applicatio­ns, such as building & constructi­on, steel industry, and ceramics & refractory, among others.

With the continued expansion of the local rice industry and the implementa­tion of Guyana’s Low Carbon Developmen­t Strategy, the industry will find itself in a win-win situation by utilising the husks for energy generation and utilising the ash as a cement extender in the building industry or preferably utilising it as the raw material to produce pure silicon for the solar energy industry. With regards to the latter, Guyana’s silica sand is the raw material for the production of the silica used for the manufactur­e of photovolta­ic cells for the solar energy industry. The process for transforma­tion however is highly energy intensive and intricate. However Guyana’s vast deposits of silica leached over time is the ideal raw material for the production of the pure silica required by the solar energy industry. This coupled with the cheaper production from available RHA can for the basis of a thriving industry in Guyana. The rehabilita­tion of Tumatumari could be tied in with an industrial complex that draws on our sand and other clay resources.

Other opportunit­ies exist in the sugar industry through use of bagasse, a technology we are familiar with. One approach to sugar is to regard it primarily as an industry generating energy, through cogenerati­on utilising the bagasse and treating sugar as a by product. Agronomic research has produced high fibre planting material that meets the specificat­ions for this type of approach. As Guyana proceeds to consolidat­e its agricultur­al sector there would be many opportunit­ies to generate energy from agricultur­al waste. IAST successful­ly implemente­d a national biogas programme. This involved the use of animal waste (livestock, pigs) to generate biogas which was used for heating, lighting and refrigerat­ion. The project developed and employed digesters for domestic and institutio­nal use. Over a four year period about ninety eight digesters were built and deployed in many communitie­s across Guyana. The recent disclosure that a large scale dairy farm is being considered as part of a project to provide dairy products for Guyana opens the door for considerat­ion of the installati­on of an industrial sized biogas plant utilising all of the animal waste that would be available. This would provide the energy required for their processing activities. Incidental­ly the slurry recovered after the fermentati­on cycle is completed is an excellent bio fertiliser which can be utilised as part of our thrust for sustainabl­e and low emission agricultur­e.

All of these activities taken together are implementa­ble and can make a significan­t contributi­on to our quest of weaning Guyana off of a fossil fuel based energy sector while at the same time contributi­ng to the profitabil­ity in the rice and timber industries, providing new opportunit­ies for industrial production from the Rice Husk Ash in the rice industry, and assisting with the management of the environmen­tal challenges posed by waste to our health and well-being. All of these actions can and should be financed using local capital and not through the usual high cost internatio­nal financing mechanisms. In our haste to address the energy issue locally let us not forget these low hanging fruit that can, with the right policy environmen­t and a progressiv­e private sector, redound to the benefit of all Guyanese and to the achievemen­t of a climate resilient and low carbon developmen­t pathway for Guyana.

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