Place dry black beans in a large saucepan.

Add water to cover the beans by 1 inch.

Bring to a boil over high heat and boil for 1 minute.

Remove the pan from heat, cover tightly, and let stand for 1 hour to soak.

Drain the soaked beans.

Combine the drained beans in a 5-quart Dutch oven or soup kettle with chicken broth, minced celery, minced carrots, minced onions, and grated lemon zest.

Bring the mixture to a boil over high heat.

Reduce heat to low and simmer uncovered for 2 1/2 to 3 hours, until the beans and vegetables are very tender and the liquid has reduced slightly.

Using a slotted spoon, transfer soup solids in batches to a food processor and puree until smooth.

Transfer the pureed mixture to a large bowl and add the cooking liquid.

Return the soup to the Dutch oven.

Stir in lemon juice, salt, and black pepper.

Cook over medium heat, stirring constantly, until heated through.

Place a lemon quarter in the bottom of each bowl.

Pour the soup into the bowls and serve immediately.