Part 1: Why
FuelThere are many, many reasons to make charcoal and biochar. My number one priority is to make a high quality cooking fuel. Cooking a hot meal is something that most people do every day. If there is any kind of short term or long term disaster cooking fuel could be in short supply very quickly. I have a charcoal smoker/grill and charcoal is expensive. I suspect I will be able to recoup all costs of building a retort in one or two batches of charcoal. The majority of my extended family also have charcoal grills so not only will this save my immediate family money but I will also be able to save my extended family money. If there is any kind of disaster we will all be able to have a hot meal. Another use for charcoal is a fuel source for a forge. It may not get as hot as real coal but it should be acceptable.
BiocharMy other main reason for building a retort is to make biochar. I won’t go into details just yet but charged, crushed up charcoal or charred biomass is an incredible soil amendment that I want to take advantage of. Instead of burning weeds, Leaves and sticks all this could be put in a forge and turned into black gold. Gabriel Hemery has a nice little article that further explains biochar.
http://gabrielhemery.com/2011/12/12/biochar-explained/Water FilteringCharcoal has an enormous surface area. This is why there are so many water filters and the market that are based on charcoal filters, including Berkey Filters. I won’t don’t know much about using charcoal as a filter but I have seen it done and I do believe I can keep my family from getting sick from drinking dirty water.
Activated CharcoalI won’t pretend to know much about this. Provided you have “cooked” your charcoal sufficiently you will have nearly pure carbon that you can use for all kinds of alignments.
http://en.wikipedia.org/wiki/Activated_carbonBiochar vs Charcoal