Skeldon Cogen Plant – Is it 20,000t/month or 100,000t/year?

Dear Editor,
Reference is made to a news item on April 21st, 2018 in the state’s newspaper, titled “Skeldon Energy seeking local suppliers of biomass”, in relation to a multi-stakeholder meeting held to source 100,000t of biofuel per year for boilers at Skeldon Sugar Factory.
Editor, before I address the subject of fuel type in relation to boiler design, it is quite glaring that Guyana Sugar Corporation (GuySuCo) and Skeldon Energy Inc (SEI) are either confused or are deliberately sending mixed messages to this nation. We recall, in November 2016, GuySuCo’s Chairman likened Skeldon to a “ticking time bomb”. In June 2017, SEI’s Chairman labelled Skeldon Cogen Plant as a “ticking time bomb”, stating that US$2.5 million is required for emergency works and US$17 million is required for long-term corrective works.
Recently, in January 2018, the Prime Minister’s0 Region Six Representative spoke highly of Cogen’s potential while citing the need for US$17 million investment and biofuel requirement of 20,000t/month, which calculates to 240,000t/year. Now, in April 2018, we learn from this official a new figure of 100,000t/year.
From these utterances, the PM’s Representative seems confused on what quantity of biofuel is required. Maybe he should clarify how his numbers are derived. Is it 20,000/month or 100,000/year? Also, I urge this official to tell us whether the US$17 million was spent, or whether the time bomb at Skeldon continues to tick.
On the subject of fuel type and boiler design, it is clear that the SEI is seeking suppliers of “paddy shell, rice straws, sawdust, coconut shells and lumber”. Editor, I fully support a comprehensive biofuel programme for a green economy initiative. However, commonsense tells us that each fuel type has its own unique characteristic, and therefore the equipment used to combust that fuel must be designed for that fuel type.
Fuel characteristics include, but are not limited to: energy value, material state, consistency, resultant residue, etc. The boilers at Skeldon Cogen Plant were designed to operate with heavy fuel oil and bagasse. Due to the application of diffusion technology in the juice extraction side at Skeldon factory, the furnaces were equipped with “pin-hole” type grates at their bases. This furnace type is highly efficient, as the design requires fuel to be suspended in air during burning. In simple terms, the fuel has to burn completely as it falls into furnace, leaving only residue (ash) to drop to the bottom, where the grate is located. The furnace becomes highly inefficient whenever fuel drops directly onto grate, simply because it blocks or restricts air-flow into the furnace, required for combustion and keeping bagasse particles in suspension. The need for finely prepared (shredded) fuel is therefore a necessity for effective and efficient operation of this design. It is part of the reason why the cane preparation system at Skeldon was equipped with two cane knives and a shredder. Bagasse fuel particle size is important.
Over the past years, efficient boiler operation at Skeldon has been plagued by poor quality bagasse, largely because of excessive soil in cane, poor cane preparation, and high moisture content. With the idea of using paddy shell, rice straws, sawdust, coconut shells and lumber at Skeldon, could the SEI team tell us how they intend to prepare these fuel types to the required consistency for suspension burning furnace? Is there any plan to modify the furnace to accommodate this fuel? What about the handling equipment for the various types of fuel? Have we studied the transport cost in relation to fuel bulk densities versus the buying price? How frequently will fuel supplied be tested for its energy value?
Editor, this is an industrial scale undertaking to use varying types of biofuel in a high-pressure boiler, and must be treated as such. It is not operation of a wood-stove or a fire pot for a few hours.

Sincerely,
Sookram Persaud