Project Briefing

Rum distillery utilities asessment was focused on 3 main areas:

1. Biomass Boiler

• Bagasse fueled boiler 
• Pre-heating air is used to dry the bagasse while traveling along the vibrating grate prior to entering the boiler.
• Boiler needs to operate at >30 bar(g) in order to have a high enough furnace temperature
• Bagasse's density and calorific value is low and dependent of cane varietal and performance of the mills
• An economiser is designed to withstand full boiler pressure thus pre-heating feedwater in excess of 100°C, this  is important for efficiency
• Turndown ratio 1:8 – all equipment on VSDs (min. turndown on feedwater pumps limited by pressure requirement i.e. 30 bar(g)

2. Organic Rankine Cycle Turbine

• ORC turbine is used as a steam load management device, otherwise, when there is no distillation taking place the steam would have to be vented.
• Cycle based on Rankine’s steam cycle expect organic refrigerants/alcohols are used in the circuit in lieu of steam
• Typically needs a heat supply and connection to cooling plant in this case steam supply of main header and cooling tower water connection
• The circulating pump on the refrigerant circuit is VSD controlled giving a good turn-down ratio (albeit at lower output the parasitic loads consume a larger portion of the useful energy produced)

3. Air Emissions Abatement:

• Feedwater economiser and air pre-heater
• Grit collector or multi-cyclone separator operates with a pressure drop > 2 kPA
• Reverse jet back filter – fitted with differential pressure instruments
• > 95% particulate reduction achievable