Thread by @WizardsUnknown

Quick 🧵on Sugar Industry and Ethanol blending:

NEED OF THE HOUR : RENEWABLE BIOMASS FUEL
One of the greatest challenges of 21st century is to meet the growing demand for energy for transportation, heating, and industrial processes.

Excessive consumption of fossil fuels, particularly in large urban areas, has resulted in generation of high levels of pollution during the last few decades.

All petroleum-based fuels can be replaced by renewable biomass fuels such as bioethanol, biodiesel, bio-hydrogen. Bioethanol is one of the most promising biofuels from renewable sources. Indian gov intends to raise ethanol blending in petrol to 20% by 2025 from the current 7%.

Ethanol, or ethyl alcohol, is a liquid that can be derived from sugarcane, corn, switchgrass etc.
At 95% purity, it is called rectified spirit and is used as the intoxicating ingredient in alcoholic beverages. At 99%-plus purity, ethanol is used for blending with petrol.

Bioethanol feedstock can be classified into three types: sugar-based feedstock, starchy materials, and lignocelluloses biomass. Today, we will discuss sugar-based feedstock.

Why ethanol from sugar?
Sugar mills have all-time-high stocks of sugar, and they have been at loggerheads with farmers over non-payment of dues. Mill owners insist that the reason behind their woes is excess production of sugar and fall in its price.

Under the circumstances, ethanol is the only real savior, both for mills and cane growers. The gov approved an increase in the price of ethanol to be procured by public sector oil marketing companies. Ethanol production has been additionally facilitated by mandating 10% blending.

Ethanol from Sugar cane: The process
Sugar cane is crushed to extract Juice out of it. The fiber left after extracting juice is called bagasse. This bagasse is used(burnt) as a fuel in co-generation power plant to generate power.

The extracted juice is processed further with chemicals and crystallized. Sugarcane typically has a total fermentable sugars (TFS) content of 14%. The TFS component consists of sucrose along with the reducing sugars glucose and fructose.

Most of this TFS component gets crystallized into sugar, and the remaining part is called molasses. This molasses will be fermented and distilled to produce ethanol.

Stages of molasses: AH, BH & CH
Direct: AH or First molasses is what is left after the sugar has been crystallized out once.
B-Heavy: When AH is re-boiled and more sugar crystallized out, the remaining syrup is second
molasses (BH).

C-Heavy: After a third time, the molasses is blackstrap molasses. Blackstrap is still the result of final boiling, which is why it’s less sweet and more strongly flavored. Molasses contains around 40% of sugar content (TFS) that is fermented by yeast.

Price comparison

Sugarcane to Ethanol: Supply chain network: Sugarcane to bagasse

Sugarcane to Ethanol:

It is clear that ethanol production is helping the sugar industry with improved visibility of revenues.

Now let’s talk about what may go wrong. India lags top producers of ethanol, the US and Brazil, by a huge margin and remains inefficient in terms of water usage. These are Aqua stat water statistics of the FAO (Food and Agriculture Organization of the United Nations) for 2013-17

For Brazil, which uses both an ethanol-petrol blend and just ethanol as fuel, the overall blend rate is 45-50%. India’s surface and ground water requirement will hugely exceed that of Brazil if India were to achieve its targeted 20% blend rate.

In order to achieve 20% blend rate, almost one-tenth of the existing net sown area will have to be diverted for sugarcane production. Any such land requirement is likely to put a stress on other crops and has the potential to increase food prices.

End of the 🧵
Cheers!🙏